export function useTheme(){
    const changeTheme=(color:any)=>{
        //获取html根节点
        let html=document.documentElement;
        //判断html标签是否有类名dark
        // dark.value?html.className='dark':html.className=''
     
        html.style.setProperty('--el-color-primary',color)
    }
    return {changeTheme}
}